Fuse construction



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W. 0. SCHULTZ FUSE CONSTRUCTIOE Filed Aug. 26, 1939 Feb. 11 1941.

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Patented Feb. 11, 1941 ruse CONSTRUCTION William 0. Schults, SouthMilwaukee, Wis, aslisnor to Line Material Company, SouthMilwaukee,Wis.,aoorporationofDelaware 7 Application August 28, 1939,Serial No. 292,040

Claims.

This invention relates to fuse constructions and is particularlydirected to a drop-out fuse.

Objects of this invention are to provide a housed type of drop-outfusewhich is so made that it may be caused to operate in either of twodifferent ways so that the fuse tube may slide downwardly and projectfrom the housing, the door remaining closed, or which, by a simplechange, may be made to operate in a diflerent manner to cause the fusetube to slide downwardly and the door to fall to open position, in bothinstances giving a visual indication of the fact that the fuse hasblown. Further objects are to provide a housed type 154 of drop-outfuse-which is so made that when the fuse tube slides downwardly, thelower por-v tion of the fuse tube assembly is dead,.and in which whenthe door either automaticaiLv drops open or is manually puiledvopen. thelower support for the fuse tube and door assembly and all parts of thefuse tube and. door assembly are dead so as to provide for the saferemoval of the.

fuse tube and door assembly and its safe replacing after refusing.

Further objects are to provide a drop-out type connect the lower portionof the fuse tube assembly with the lower stationary terminal but insteadin which the spring is effective during the major portion of the slidingmotion, but during the latter portion of the sliding motion isineffective and is so held that the electrical connection to the lowerpart of thefuse tube assembly is interrupted. Further objects are toprovide a drop-out type of fuse in which a fuse link extracting means iscarried by the fuse tube adjacent the open end, in which the coiledspring surrounding the fuse tube operates to urge the fuse tubedownwardly and to cause fuse link extracting motion of the fuse linkextracting means, the fuse link extracting means being carried by thefuse tubemember is carried by the fuse tube and ensues arelativelystationary member, the fuse link extracting means being normally held bythe fuse link andholding the fuse tube in its elevated or operativeposition and upon blowing of the fuse link first operating as a fuselinkextracting 'tacts are provided which are so made that a very attachthe lead-in conductors with ease, thecon- PATENT OFFICE means andthereafter detaching itself from the relatively stationary member andbecoming electrically dead, the fuse link extracting means being pivotedclosely adjacent the relatively stationary member so that a small motionof thefuse tube results in a rapid withdrawal of the fuse link tothereby insure interruption of the circuit within the fuse tube prior tothe time that the terminals of the fuse tube move away from thestationar terminals.

Further objects are to provide a construction in which the same springactuates the fuse tube for sliding motion and also actuates the fuselink extracting member, the fuse link extracting member being, asstated, carried by the fuse tube itself and detachably interlocking witha relatively stationary portion of the apparatus.

Further objects are to provide a fuse construction in which novel formsof stationary consimpie lead-in attaching member is furnished and isarranged for easy manipulation from directly in front of the fuse box sothat the lineman may struction also being relatively cheap and easy toproduce.

Embodiments of the invention are shown in the accompanying drawings, inwhich:

Figure l is aside elevation, partly in section with parts broken away,showing the device in operative position and mounted vertically.

Figure 2 is a small side elevation showing the device mounted in aslanting position.

Figure 3 is a fragmentary sectional detail of the lower portion of thedevice, showing the position of the parts after rupture of the fuse linkwhen the device is adjusted to hold the door closed.

Figure 4 is a sectional detail on the line 4-4 of Figure 1.

Figure 5 is a bottom view of the device.

Figure 6 is a sectional view on the line 6-5 of Figure 1.

Figure 'l is a fragmentary sectional view on the line 1-1 of Figurei. I1

Figure 8 is a view of the fuse tube and door assembly removed from thehousing and partly in section and partly broken away. Figure 9 is a viewcorresponding toFigure 3, showing the position of the parts when thedevice is so adjusted as to have the door and fuse tube assembly drop toopen position upon blowing of the fuse link.

Figure 10 is a fragmentary vertical sectional view showing a furtherform of stationary contact.

Figure 11 is a horizontal sectional view of the Structure shown inFigure 10.

Referring to the drawings, it will be seen that the device comprises aporcelain housing I pro vided with a door 2 formed of insulatingmaterial, such as a phenolic condensation compound. The door may beprovided with a handle or eyelet portion 3. The housing is provided withan upper stationary contactindicated generally at 4 and a lowerstationary contact indicated generally at 5 and with the usualintermediate barrier 6.

The upper and lower contacts areprovided with reversely turned L-shapedmembers I and 8 respectively which may be of strap metal and which haveangularly turned ends Q-and I0 cemented,

leaded, or otherwise secured within recesses formed in the housing. Thehousing also carries a lower support which includes a pair of hookshapedtrunnion supporting members I'I joined by a transverse web I2 andvertical end walls II.

The. upper stationary contact includes a pair of spaced laminated springfingers I4 joined by a transverse portion I5. This transverse portion issecured by means of screws I6 to the member I and preferably adownwardly extending, forwardly turned spring finger I1 is provided fora purpose hereinafter to appear.

A pair of bolts or screws I8 extend through the portions I5 and I an arethreaded into a clamping plate I9, the clamping plate clamping theincoming lead 20 in place in a very simple manner. It is preferable toform the members I8 with polygonal heads and also to provide a slot insuch members for the reception of a screw driver so that the lineman'may use either a socket whench or a screw driver in securing the linewires in place.

The lower stationary contact includes the spaced laminated springfingers 2I which are provided with downwardly turned portions 22 havingrounded outwardly turned ends. These spring fingers are joined by atransverse portion 23 which, similarly to the upper stationary contact,are held in place by means of screws 24. Bolts or screws 25 extendthrough the'portions 23 and 8 and are threaded into the clamping plate26 which clamps the lower lead-in conductor 21 in place.

It is to be noted that the incoming leads may be easily inserted inbetween the clamping plates and the adjacent portion of the contacts,and that the lineman may, by means of a screw driver or a socket wrench,manipulate such bolts or screws from the front of the housing in a verysimple and easy manner to clamp the conductors in place.

The door carries a sleeve or guide 28 which slidably receives theexpulsion fuse tube 2!, such fuse tube being provided with an upperscrew cap 30 'which clamps the upper button-head of the fuse link inplace in the usual manner as shown in Figure 8.

The sleeve 28 is provided with-a pair of laterally projecting lugs 22'which are received behind- 3| adjacent its upper end and with a flexibleleader 32 which projects outwardly through the bottom end of the fusetube and is preferably guided through a notched portion 33, see Figure8.

The upper contact of the fuse tube is indicated at 24 and is providedwith a pair of lugs or ears 35 which project outwardly and are receivedbeneath the spring fingers I4. The contact 34 also bears against thespring finger I1, see Figure 1, and this spring finger holds the lugs 35against the slightly downwardly turned cam like portions I4 of thespring fingers I4. Further, it will be seen from reference to Figures 1and 7 that the upper contact 24 of the fuse tube has a flat rear faceand that the spring finger I1 has relatively extensive contact area withthis flat face and consequently serves to carry some of the current fromthe upper stationary contact to the upper contact of the fuse tube.

The guiding sleeve 28 is secured to the door as stated and slidablyreceives the fuse tube 29. Normally the upper contact 34 of the fusetube bears against a projecting portion 36 of the door. The guidingsleeve 28 extends rearwardly as indicated at 31, see Figures 1, 3, 8 and9. This rearwardly extending portion or arm 3'! of the sleeve 28 isprovided with an aperture 38, see Figure 8, which has a lower wall orabutment I! for a purpose hereinafter to appear. The arm is alsoprovided with a pair of outwardly projecting trunnions 40 which areremovably received within the hook supports I I of the housing. Thesleeve 24 is also provided with a socket portion, see Figure 8, withinwhich a coiled spring 42 is normally housed, such coiled spring looselysurrounding the fuse tube and having a projecting arm 44 bearing againsta shouldered portion on the door 2 to prevent the spring from slidingdownwardly on the fuse after the fuse has blown and after the parts havemoved to the position shown in Figure 3 for example. The lower end ofthe spring bears against a collar 44 rigidly secured to the fuse tubeadjacent its lower open end.

The collar 44 is integral with a rearwardly projecting arm 45 which fitsinto a slot formed in a lever 46 and is pivoted to such lever by meansof the pintle pin 41. The lever 46 is provided with a projectingthreaded stud 48 upon which a thumb nut 49 is carried to clamp theflexible leader. 32 in place, such lever being preferably provided witha lug 50, see Figure 8, behind which the free end of the leader may bepositioned. The lever 44 is cut out to provide a rounded or recessedportion 5| at its outer end which conforms approximately to the fusetube, as shown most clearly in Figure 5. This outer end of the lever 44bears against the lower portion of the collar 44 under normalconditions, as shown in Figures 1 and 8.

Upon reference to Figures 1, 5 and 8, it will be seen that the leader I201' the fuse link is passed over the outer end of the lever 46 and overthe laterally projecting lug 52 of such lever, as shown in Figure 5. Theleader extends up the side oi the lever and is clamped beneath the thumbnut 40, as is apparent from an inspection of Figures 1, 5 and 8.

It is to be noted particularly that the outer end of the lever 44 isprotected by the fuse tube against the incandescent gases projected fromthe bottom of the fuse tube upon blowing of the fuse, and also it is tobe noted that the motion of the lever 44, which constitutes a fuse linkextracting member, is downwardly as it rocks about the pivot pin 41, andthus any remaining portion of the fuse link is drawn substantiallydownwardly from the open lower end of the fuse tube.

Itis apparent from the description thus far given that upon rupture ofthe fuse link, the spring 42 bearing against the collar 44, see Figure8, will force the fuse tube downwardly and thus will carry the pivot pin41 downwardly. However, the lever 46 is provided with a rearwardlyprojecting tongue 53 which fits within the aperture 38 of the arm 31,which latter is rigid with the sleeve 28. This tongue 53 bears againstthe supporting surface 39,

As the fuse tube is forced downwardly by the action of the spring 42assisted by gravity, it

is apparent that the fuse link extracting member or lever 48 will becaused to rock about the pin 4! during the initial downward motion ofthe fuse'tube, and it will be seen further that a very slight travel ofthe fuse tube downwardly, insufficient to remove the lug 35 of the uppercontact 34 of the fuse tube from the spring fingers l4, will result in avery extensive and rapid motion of the outer end of the lever 46, thusquickly withdrawing any remaining portion of the fuse link andinterrupting the circuit within the fuse tube prior to the parting ofthe upper stationary contact and the upper contact of the fuse tube.

The fuse tube is projected downwardly by the It is to be notedparticularly from reference to Figures 1. and 6, that the sleeve 28 isadapted to receive a pair of screws 54 which are left in place when itis desired to have the door remain closed and only the fuse tube toslide downwardly and outwardly to the position shown in Figure 3.

In order to retain the door closed, a U-shaped latch spring 55 isprovided and is carried by the lower stationary contact indicatedgenerally'at 5. The forward ends of the latch spring or latch member 55are inturned as indicated at 56 in Figures 4 and 6. These inturnedportions are positioned in front of the screws 54 and thus keep the doorfrom falling open. However, it is apparent that the door may be pulledopen either when the fuse link is intact or after the fuse link hasblown, as in the first case the latch spring 55 and the upper springcontact l4' and the lower spring contact 2| will yield to allow theopening of the door.

If it is desired to have the door drop open upon blowing of the fuselink, the screws 54 are removed and consequently the door is held closedby the engagement of the upper spring fingers I4 with the lugs 35, seeFigure 1, and when the fuse tube drops downwardly, the door is releasedand the fuse tube and door assembly will rock open to the final positionshown in Figure 9.

It is obvious that when the fuse tube and door assembly drop to openposition, that the lower supports H and the entire fuse tube assembly iselectrically dead. It is also clear that when the door stays closed andthe fuse tube slides downwardly, as shown in Figure 3, that the lowerportion of the fuse tube assembly, that is to say,

the collar 44, the arm 45 and the lever 46, are electrically dead, andtherefore after the fuse blows, no matter which adjustment is provided,there is no live part projecting outwardly from the housing.

A further form" of stationary contact which may be used for either theupper or lower stationary contact is shown in Figures and 11. This formdiffers from that previously described in that the supporting memberconstituting a part of the stationary contact is of roughly U- shape, asshown most clearly in Figure 11, and is indicated by the referencecharacter 51. It has rearwardly projecting arms which are cemented,leaded or otherwise secured to the housing l. .The supporting member 51is formed from strap metal and is provided with the transverse,relatively flat portion 58 to which the laminated contact is secured,such contact being indicated by the reference character 59. The contactmay be similar to those previously described and may be either the upperor the lower contact, or of any other type desired.

The U-shaped supporting member 57 is relatively heavy and receives thescrews 60 which secure the contact 59 in place.- Further, bolts 8| passthrough the contact and through the supporting member 51 and arethreaded into the conductor clamping plate 62 corresponding identicallyto that previously described so that when the screws or bolts 6| aretightened, they draw the clamping plate forwardly and thus serve toclamp a lead-in conductor in place.

It is preferable to notch out the lower portion of the supporting member51 as indicated at 53 to facilitate insertion of the lead-in conductor.

In both forms of supporting member it is apparent that a small bentstrip of strap metal may be employed. In the form previously described,the strap metal is generally horizontal, whereas in the form shown inFigures 10 and 11 the strap metal is essentially vertical.

It is to be notedthat whichever type of supporting means is employed forthe stationary contacts. that such supporting means is very easy to formand may be cheaply produced.

It is to be noted from reference to Fignres 1 and 3 that the rearwardlyprojecting arm 31 of the sleeve 28 is positioned beneath the lower staisprovided with a rounded portion 3i" which fits beneath the overhangingportion l2 of the'hook supports ll under normal conditions andconsequently prevents inadvertent detachment of the trunnions 40 fromthe hook supports Ii. However, when the fuse tube and door assembly arerocked to open position, this rounded portion clears the overhangingportion l2, as shown in Figure 9, and allows the trunnions to be readilydetached from the hook supports.

It is apparent that when the fuse tube projects downwardly from thehousing, as shown in Figure 3, although the door remains closed, that avisual indicationis given that the fuse has blown. Similarly when thedoor and fuse tube eration of the device, and that the fuse link ex'-tracting means rapidly withdraws any remaining portion of the fuse link.Also it will be seen that this fuse link extracting member is protectedfrom the incandescent blast of gases from the fuse tube, and that itdoes not obstruct the bore of the fuse tube in any manner whatsoever.Further, the motion of the outer end of the fuse link extracting memberor lever is substantially downwardly and thus there is very littlefrictional drag on theleader against the side of the fuse tube.

It will be seen that this fuse device can be supplied to customers andthe customers can adlust such devices so that either the door staysclosed or drops open, depending upon the desire of the particularcustomer.

Although this invention has been describedin considerable detail, it isto be understood that such description is intended as illustrativerather than limiting, as the inventionmay be variously embodied and isto be interpreted as claimed.

I claim:

l. A drop-out fuse construction comprising supporting means, stationarymeans carried by said supporting means and including stationarycontacts, an expulsion fuse tube having an open end, fuse linkextracting means carried by the fuse tube adjacent said open end, asleeve supported from said supporting means and slidably holding saidfuse tube, said fuse link extracting means engaging a part of saidsupporting means distinct and separate from said sleeve and detachablyinterlocking with said part and moving away from said part when saidfuse tube slides with reference to said sleeve, and a fuse link withinsaid fuse tube normally electrically connecting said stationary contactsand restraining said fuse link extracting means against motion.

2. In a drop-out fuse construction, stationary means having stationarycontacts, an expulsion type fuse tube, a fuse link within said fuse tubenormally electrically connecting said stationary contacts, supportingmeans including a sleeve slidably holding said fuse tube, an abutmentcarried by said supporting means and distinct and separate from saidsleeve, and a combined fuse link extracting and fuse tube restrainingmember movably carried by said fuse tube and normally restrained by saidfuse link and directly detachably interlocking with said abutment, saidcombined fuse link extracting and fuse tube restraining member beingbodily movable with said fuse tube when said fuse tube slides throughsaid sleeve and moving away from engagement with said abutment.

3. In a drop-out fuse construction, stationary means having stationarycontacts, an expulsion type fuse tube, a fuse link carried within saidfuse tube and normally electrically connecting said stationary contacts,a sleeve slidably carrying said fuse tube, said fuse tube having an openend, an arm carried by said fuse tube adjacent the open end andprojecting laterally from said fuse tube, a combined fuse linkextracting and fuse tube restraining member including a lever pivotallycarried by said arm and having a forwardly projecting end adjacent saidfuse tube and normally held by said fuse link, and an abutment supportedfrom said stationary means and laterally spaced from said sleeve, saidlever having a rearwardly projecting end normally engaging said abutmentand restraining said fuse tube against sliding motion within said sleeveuntil released upon rupture of said fuse link.

4. In a drop-out fuse construction, stationary means having stationarycontacts, an expulsion from said fuse tube, a combined fuse link ex-'tracting and fuse tube restraining member including a lever pivotallycarried by said arm and having a forwardly projecting end adjacent saidfuse tube and normally held by said fuse link, and an abutment supportedfrom said stationary means and laterally spaced from said sleeve, saidlever having a rearwardly projecting end normally engaging said abutmentand restraining said fuse tube against sliding motion within said sleeveuntil released upon rupture of said fuse link.

5. In a drop-out fuse construction, stationary means having stationarycontacts, an expulsion type fuse tube, a fuse link carried within saidfuse tube and normally electrically connecting said stationary contacts,a sleeve slidably carrying said fuse tube, said fuse tube having an openend, an arm carried by said fuse tube adjacent the open end andprojecting laterally from said fuse tube, a combined fuse linkextracting and fuse tube restraining member including a lever pivotallycarried by said arm and having a forwardly projecting end adjacent saidfuse tube and normally held by said fuse link, and an abutment supportedfrom said stationary means and laterally spaced from said sleeve, saidlever having a rearwardly projecting end normally engaging said abutmentand restraining said fuse tube against sliding motion within said sleeveuntil released upon rupture of said fuse link, said lever having meansfor the attachment thereto of said fuse link.

6. In a drop-out fuse construction, an expulsion fuse tube having anopen end, a fuse link extracting member carried by the fuse tubeadjacent said open end, stationary contacts, a sleeve slidably holdingsaid fuse tube, means spaced from said sleeve and detachablyinterlocking with said fuse link extracting member for restraining saidfuse tube against sliding, and a fuse link within said fuse tubenormally electrically connecting said stationary contacts andrestraining said fuse link extracting member against motion, said fuselink extracting member being moved by the sliding motion of said fusetube upon rupture of said fuse link to extract any remaining portion ofthe fuse link.

7. In a drop-out fuse construction, an expulsion fuse tube having anopen end, a fuse link extracting member carried by the fuse tubeadlacent said open end, stationary contacts, a sleeve slidably holdingsaid fuse tube, a spring biasing said fuse tube for sliding motionthrough said sleeve, means spaced from said sleeve and detachablyinterlocking with said fuse link extracting member for restraining saidfuse tube against sliding, and a fuse link within said fuse tubenormally electrically connecting said stationary contacts andrestraining said fuse link extracting member against motion, said fuselink extracting member being moved by the sliding motion of said fusetube upon rupture of said fuse link.

8. In a housed drop-out fuse construction, a housing, a door for saidhousing, supporting means supported from said housing and carrying saiddoor and including a sleeve, spring means biasing said fuse tube forsliding motion through said sleeve, said housing having stationary con-75 tacts, a fuse tube slidably carried by said sleeve,

housing, a door for said housing, supporting means supported from saidhousing and carrying said door and including a sleeve, a springencircling said fuse tube and biasing said fuse tube for sliding motionthrough said sleeve, said housing having statonary contacts, a fuse tubeslidably carried by said sleeve, a fuse link within said fuse tubenormally electrically connecting said stationary contacts, an abutmentcarried by said supporting means and spaced from said sleeve, and a fuselink extracting member carried by said fuse tube and detachablyinterlocking with said abutment and controlled by said fuse link.

10. A housed type of drop-out fuse comprising a housing, a fuse tube anddoor assembly, supporting means including pivot means for supportingsaid fuse tube and door assembly from said housing, said fuse tube beingmounted to drop outwardly from operative to inoperative position,restraining means carried by said fuse tube and movable therewith, anda, fuse link within said fuse tube, said restraining means comprising alever cooperating with said supporting means adjacent said pivot meansand moving away from said supporting means when said fuse tube moves toinoperative position, said lever having fuse link clamping means.

11. A housed type of drop-out fuse comprising a housing, a fuse tube anddoor assembly, supporting means including pivot means for supportingsaid fuse tube and door assembly from said housing, said fuse tube beingmounted to drop outwardly from operative to inoperative position, an armrigidly carried bysaid fuse tube and projecting laterally therefrom, afuse link within said fuse tube, and a lever pivotally mounted on saidarm and normally restrained against motion by said fuse link andcooperating with said supporting means adjacent said pivot means tooutwardly from operative to inoperative position, an arm rigidly carriedby said fuse tube and projecting laterally therefrom, a fuse link withinsaid fuse tube, and a lever pivotally mounted on said arm and having aforwardly extending portion beneath which said fuse link is looped I andhaving fuse link attaching means and having a rearwardly projectingportion cooperating with said supporting means adjacent said pivot meansand moving away from said supporting means when said fuse tube moves toinoperative position. j

13. A housed type of drop-out'fuse comprising a housing, a fuse tube anddoor assembly, supporting means including pivot means for supportingsaid fuse tube and door assembly from said housing, said fuse tube anddoor assembly being biased towards outward swinging motion carried bysaid. fuse tube and projecting laterally therefrom, a fuse link withinsaid fuse tube, and a lever pivotally mounted on said arm and normallyrestrained against motion by said fuse link and cooperating with saidsupporting means adjacent said pivot means to restrain said fuse tubeagainst motion and moving away from said supporting means when said fusetube moves to inoperative position, said fuse tube and doorassemblyrocking outwardly from said housing after motion of said fusetube.

14. A housed type of drop-out fuse comprising a housing, a fuse tube anddoor assembly, supporting means including pivot .means for supportingsaid fuse tube and door assembly from said housing, said fuse tube beingmounted to drop outwardly from operative to in-- 15. A housed type ofdrop-out fuse compris- \ing a housing, a fuse tube and door assembly,

supporting means including pivot means for supporting said fuse 'tubeand door assembly from said housing, said fuse tube and door assemblybeing biased towards outward swinging motion with reference to saidhousing, an arm rigidly carried by said fuse tube and projectinglaterally therefrom, a fuse link within said fuse tube, and a leverpivotally mounted on said arm and normally restrained against motion bysaid fuse link and cooperating with said supporting means adjacent saidpivot means to restrain said fuse tube against motion and moving awayfrom said supporting means when said fuse tube moves to inoperativeposition,

and means for selectively allowing or preventing said door from. rockingoutwardly when said fuse tube moves to inoperative position.

16. A housed type of drop-out fuse comprising a housing, a fuse tube anddoor assembly, supporting means including pivot; means for supportingsaid fuse tube and door assembly from said housing, said fuse tube anddoor assembly being biased towards outward swinging motion withreference to said housing, an arm rigidly carried by said fuse tube andprojecting laterally therefrom, a fuse link within said fuse tube, and alever pivotally mounted on said arm and normally restrained againstmotion by said fuse link and cooperating with said supporting meansadjacent said pivot means to restrain said fuse tube against motion andmov- 17. In a drop-out fuse construction, an ex pulsionfuse tube havingan open end, a collar carried by said fuse tube adjacent said open end,a fuse link extracting member supported from said collar, stationarycontacts, a sleeve -s1idably holding said fuse tube, a springsurrounding said fuse tube and normally bearing carried by said fusetube adjacent said open end, a fuse link extracting member supportedfrom. said collar, stationary contacts, a sleeve slidably holding saidfuse tube, a. spring surrounding said fuse tube and normally bearingagainst said collar for urging said fuse tube towards sliding motionthrough said sleeve, means detachably interlocking with said fuse linkextracting member for restraining said fuse tube against sliding, and afuse link within said fuse tube normally electrically connecting saidstationary contacts and restraining said fuse link extracting member.gainst motion, said spring being held out of contact with said collarwhen said fuse tube has slid outwardly with reference to said sleeve,said fuse link extracting member moving with said fuse tube out ofengagement with said means and being electrically dead when said fusetube has moved to inperative position.

19. A stationary contact construction comprising a relatively rigidmember adapted for attachment to a suitable supporting means and havinga relatively flat end portion, yielding contact means secured to saidrelatively flat portion, a conductor clamping plate located adiacentsaid relatively flat end portion, and attaching means accessible fromthe front for,

drawing said plate towards said relatively flat end portion for clampinga conductor between said plate and said relatively flat end portion.

20. A stationary contact construction for an electrical devicecomprising a relatively rigid fiat strap member adapted to be secured toa suitable supporting member and having an anguiarly bent relativelyflat end portion, yielding contact means secured to the front side ofsaid angularly bent end portion, a conductor clamping plate locatedrearwardly of said angulariy bent end portion, and attaching meansextending through said angularly bent end portion and accessible fromthe front and threaded into said clamping plate, whereby said clampingplate may clamp a conductor between itself and the rear face of saidangularly bent end portion.

WILLIAM O. SCHULTZ.

